General Comments on Tolerancing Limits
This represents a general list of soft limits and is intended for reference only.
Reducing tolerance range increases costs.
Robust sensitivity analyses will help yield the most cost-effective tolerancing.
Tolerancing Limits for Cylinder Surfaces
| wdt_ID | Attribute | Cylinder Tolerancing Limit |
|---|---|---|
| 1 | Glass Quality (nd, vd) | Melt Rebalanced and Controlled |
| 2 | Length and width (mm) | +0, -0.020 |
| 3 | Center Thickness (mm)³ | ± 0.020 |
| 4 | Sag – Concave (mm) | ± 0.020 |
| 5 | Clear Aperture | 100%⁴ |
| 6 | Radius⁵ | ± 0.1% or 3 HeNe fringes⁶ |
| 7 | Irregularity – Interferometry (HeNe fringes)⁷ | 0.1⁸ |
| 8 | Irregularity – Profilometry (μm) | ± 0.5 |
| 9 | Plano Axis Wedge – ETD (mm) | 0.005¹² |
| 10 | Cylinder Axis Decentration – TIR (mm)⁹ | 0.010¹⁰ |
| 11 | Axial Twist Angle (arcminutes) | 3 |
| 12 | Bevels – Face Width @ 45° (mm)¹¹ | 0/0mm max |
| 13 | Scratch – Dig (MIL-PRF-13830B)¹² | 10 – 5 |
| 14 | Surface Roughness (Å RMS)¹³ | 5 |
- This is for the most well behaved materials. More difficult materials (CaF2, Ohara S-FPL, etc.) will need larger tolerance ranges.
- Of full aperture (FA).
- In addition to irregularity.
- Whichever is correspondingly larger over the clear aperture.
- Typical metrology is Zygo MetroPro plots for interferometry.
- As geometry requirements move closer to a min or max shown the less likely this is possible.
- Optimax measures total indicated runout (TIR) as part is rotated. Actual decentration varies with focal length.
- This specification is extremely tight and expensive. For a more economical limit, please consider using 0.0100mm.
- Subject to measurement uncertainty.
- Crystals and reflective materials will receive 40W inspection.
- This represents lowest values obtained. Actual values for crystalline, especially polycrystalline materials, will be higher.
For more detailed information on any attribute, please contact sales@optimaxsi.com.